Yes, engine has to come out of the frame to get the cylinder off. It's really easy though. Tip: Put the bike on the center stand, and put a book or a block of wood under the rear tire. Now when you remove the swingarm bolt, nothing will move. In this way, you don't have to remove the rear wheel and swingarm first. Saves some time. Also get the bolt-on downtubes that run under the engine off before you unbolt anything else. I put a jack under the engine and balanced it as I took the last bolt out. Then I just picked it up and put it on my workbench. It's not very heavy.

Charles.

Thanks a lot I was worried about the swingarm, now I know that the bike will not turn over by the way I contacted the Chinese guy about the rear shock absorber I want to replace it with a longer one, but it turned out that the spring is 11.5 mm and such a shock absorber is quite expensive about 150$ I have to pull it out and give the exact dimensions to the Chinese guy.

I cut my dog bones and removed 6mm and welded them back together to get a little more ride height.

Charles.

I think a longer shock with a longer spring would be better than the stock one, but if it turns out the spring is the same length but the shock is longer then I'll buy a $60 dollar shock with a 7mm spring only and put mine on. Generally a spring like the one in the rx3 costs about $100.